1. Field of the Invention
The present invention relates to a vehicle-mounted navigation system for guiding a vehicle to a destination. More particularly, the present invention relates to a vehicle-mounted navigation system which enables calculation of a precise arrival time even when a commercial vehicle travels to a destination by way of a number of en route points and which enables fast travel to a destination by way of en route points. Further, the present invention relates to a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with the vehicle-mounted navigation system.
The present application is based on Japanese Patent Application No. Hei. 11-292536, which is incorporated herein by reference.
2. Description of the Related Art
In a case where a vehicle travels to a destination by way of number of en route points, a related vehicle-mounted navigation system (as developed by Yazaki corporation of Japan) computes an arrival time in accordance with a flowchart shown in FIG. 10.
As can be seen from the flowchart shown in FIG. 10, conventional computation of an arrival time involves a driver entering a start point, a destination, and en route points (S1001). At this time, a driver enters these items by utilizing a map or address search function or by selecting these items from a registration list and entering the selected items.
Entry (S1001) of a destination, i.e., a desired location, will now be described by reference to a flowchart shown in FIG. 11.
A determination is made as to whether or not a desired location is registered in a registration list (S1111). If the desired location is registered in the registration list, the desired location is selected from the registration list and entered (S1102). In contrast, if the desired location is not registered in the registration list, it is retrieved by utilizing a map or address search function (S1103). When the desired location is retrieved, a determination is made as to whether or not the location is to be registered in the registration list (S1104). If the location is to be registered, a registration operation is performed (S1105), and the driver selects the thus-registered location (S1102), wherewith entry of a desired location is finished. In contrast, if the location is not to be registered, the driver selects the location (S1102) without the system performing a registration operation (S1105), wherewith entry of the desired location is finished.
Turning again to the flowchart shown in FIG. 10, a destination and en route points are entered (S1001). At step 1002, it is decided whether or not to start retrieval of a route. If the thus-entered locations are correct, retrieval of a guide route is commenced (S1002). If one or more of the thus-entered points are incorrect, processing returns to step S1001, wherein a destination and en route points are re-entered. When retrieval of a guide route is commenced, the current time is determined (S1003). The guide route is then retrieved (S1004) and, subsequently, there is computed an arrival time (1005) at which a vehicle is to arrive after having started travel along the guide route from the thus-determined current time.
However, computation of an arrival time performed by the related vehicle-mounted navigation system does not allow entry of period of stopping at each of en route points. Therefore, when arrival time is computed, errors inevitably arise in the arrival time. Further, in a case where a vehicle does not depart at a current time, but is to depart several hours later, an error arises in a computed arrival time because the related vehicle-mounted navigation system does not allow for entry of a departure time. Therefore, when arrival time is thus computed, it is incorrect.
In the related vehicle-mounted navigation system, the driver must enter a destination and an en route point. The driver retrieves a destination by retrieving such a destination from a registration list or by using a map or location retrieval function. Next, the driver retrieves the en route points by using a map or location retrieval function. The driver then enters the thus-retrieved destination and en route points. In connection with destinations which are frequently used, the destinations may be registered in a registration list. However, in connection with destinations which are less frequently used, registration of all such destinations is burdensome. Further, even in the case of a destination which has already been registered, a driver must retrieve the en route points again by using a map search function and must then enter the thus-retrieved locations. Therefore, wasteful iteration of operations is required, which results in low operation efficiency. A route retrieval function of a related vehicle-mounted navigation system (as developed by Yazaki corporation of Japan) searches for a route without taking into consideration a direction in which a vehicle approaches a destination or an en route point. There may arise a case where a destination is located on the right side with respect to the travel direction of a vehicle. In countries where vehicles travel on the left side, a median strip may hinder the vehicle""s approach to the destination. Further, since a commercial vehicle requires loading or unloading of freight into or from the vehicle, the vehicle must be parked parallel to the destination. Even in the case of a road without a median strip, the vehicle must be parked on the left side with respect to the travel direction of the vehicle. However, in a case where a positional relationship shown in FIG. 12 exists between a starting location and a destination, the related vehicle-mounted navigation system retrieves a destination in preference to minimizing time and distance, as a result of which a route R is retrieved. Thus, the related vehicle-mounted navigation system is incapable of searching for a route such that a destination is located on the left side with respect to the travel direction of the vehicle.
The related vehicle-mounted navigation system has only a time-prioritized search function and a distance-prioritized search function so that it chooses a route which minimizes time and distance. Therefore, the related system cannot reflect a driver""s desire in the route to be retrieved. For instance, every driver knows his own familiar roads which he uses everyday. However, the related vehicle-mounted navigation system searches for a route without taking into consideration such roads. Hence, even in a case where a driver desires to use his familiar road, a related vehicle-mounted navigation system (as developed by Yazaki corporation of Japan) encounters difficulty in retrieving such a road. Hence, if a driver desires to set a familiar route, he must perform a wasteful operation for setting an en route point.
A commercial vehicle may have a large body. In such a case, a driver may desire to perform detailed settings in order to prohibit a U-turn, in order to decrease the number of turns, and in order to make right turns in preference to left turns. However, a related vehicle-mounted navigation system (as developed by Yazaki corporation of Japan) has only a retrieval function which prioritizes straight-ahead driving, and is incapable of performing a search in consideration of straight-ahead travel, right turns, left turns, and U-turns. Even when a driver desires to have right turns in preference to left turnsxe2x80x94to make driving his large vehicle easierxe2x80x94the navigation system searches a route R1 which is shown in FIG. 13 and minimizes a distance to the destination. If another route R2 is taken, the number of left turns may be diminished. However, the related vehicle-mounted navigation system does not search such a route.
The present invention has been conceived in light of the foregoing background and is aimed at providing a vehicle-mounted navigation system which enables a commercial vehicle quickly to reach a destination by way of a plurality of en route points, and which enables a user""s desire to be accounted for when retrieving a route. Further, the present invention is aimed at providing a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with the navigation system.
To attain the foregoing and other objects, the present invention provides a vehicle-mounted navigation system which detects a current position of a vehicle and retrieves a route to a set destination, thereby guiding the vehicle along the route, the system including:
a route setting device into which there is entered route setting information desired by a user, said route setting information including a starting location, a destination, and an en route point;
a time setting device into which there are entered scheduled time at which the vehicle is to depart the starting location and a period of stopping at the en route point entered to the route setting device, wherein said time setting device sets departure time as a current time if the departure time is not entered; a route retrieval device which retrieves a route, to the destination, in accordance with the route setting information entered to the route setting device; and
an arrival time computation device which computes the time, at which the vehicle is to arrive at the destination, on the basis of the route retrieved by the route retrieval device, and on the basis of the period of stopping and one of the scheduled departure time and the current time, entered to the time setting device.
According to the present invention, since an arrival time is computed by accounting for a scheduled departure time and scheduled periods of stopping at en route points, an accurate arrival time can be computed even when freight is loaded and unloaded into and from a vehicle at a number of en route points.
Preferably, the route setting device preserves locations which have been entered in the past as a location history list, and allows the user to select a starting location, a destination and an en route point from the location history list to thereby determine the starting location, the destination and the en route point.
According to the present invention, because locations which have been entered in the past are preserved in the history list, a location which is less frequently used can be selected from the history list without having to register the location in the registration list. Also, a location can be entered quickly without performing a burdensome retrieval operation, such as a map retrieval operation or a name retrieval operation.
Preferably, when selecting a route, the route setting device can account for a weight arbitrarily assigned to each of straight-ahead travel, a right turn, a left turn, and a U-turn.
According to the present invention, a weight to be assigned to each of straight-ahead travel, a right turn, a left turn, and a U-turn can be arbitrarily entered by the user in accordance with the user""s desire.
Preferably, the route retrieval device preserves at least one route previously utilized by the user as a route history list, and retrieves a route by prioritizing the at least one route preserved in the route history list. That is, the route used most frequently is given the highest priority, the route used second-most frequently is given second-highest priority, and so on for all the routes in the history list.
According to the present invention, since a route with the highest priorityxe2x80x94among those including the entered en route and/or destination pointsxe2x80x94is retrieved, a route satisfying the user""s desire is retrieved. The user is thus guided to drive a vehicle along the road which the user uses everyday, thereby enabling the user to drive safely.
The present invention also provides a vehicle-mounted navigation system which detects a current position of a vehicle and retrieves a route to a set destination, thereby guiding the vehicle along the route, the system including:
a route setting device into which there is entered route setting information desired by a user, said route setting information including a starting location, a destination, an en route point, and at least one of a direction in which the vehicle is to approach the destination and a direction in which the vehicle is to approach the en route point; and
a route retrieval device which retrieves a route to the destination on the basis of the route setting information entered to the route setting device such that the direction in which the vehicle is to approach at least one of the destination and the en route point matches an approach direction set by the user.
Accordingly, the present invention avoids a case wherein a median strip may hinder the vehicle""s approach to a destination, or a case wherein a commercial vehicle may not be able to load or unload freight. Therefore, a commercial vehicle can arrive quickly at a destination by way of a number of en route points.
Preferably, in the case of left-side driving, the route retrieval device retrieves a route such that at least one of the destination and the en route point is situated on the left side of the vehicle when the vehicle approaches the destination or the en route point. Similarly, in the case of right-side driving, the route retrieval device retrieves a route such that at least one of the destination and the en route point is situated on the right side of the vehicle when the vehicle approaches the destination or the en route point.
Accordingly, the present invention avoids a case where, in the case of left-side driving, a commercial vehicle approaches a destination from a direction in which the destination is situated on the right side of the vehicle so as to prevent the loading or unloading of freight despite a necessity to do so. Alternatively, the present invention avoids a case where, in the case of right-side driving, a commercial vehicle approaches a destination from a direction in which the destination is situated on the left side of the vehicle so as to prevent the loading or unloading of freight despite a necessity to do so.
The present invention also provides a recording medium, such as a computer readable medium, having recorded thereon a processing program for use with a vehicle-mounted navigation system, which system detects a current position of a vehicle and retrieves a route to a set destination, thereby guiding the vehicle along the route, the program including:
a route setting operation for entering route setting information desired by a user, said route setting information including a starting location, a destination, and an en route point;
a time setting operation for entering a time at which the vehicle is scheduled to depart the starting location, and for entering a period of stopping at the en route point entered in the route setting operation, and for setting as a departure time a current time if the departure time is not entered;
a route retrieval operation for retrieving a route, to the destination, in accordance with the route setting information entered to the route setting operation; and
an arrival time computation operation for computing the time, at which the vehicle is to arrive at the destination, on the basis of the route retrieved by the route retrieval operation and on the basis of the period of stopping and one of the scheduled departure time and the current time, entered in the time setting operation.
According to the present invention, the arrival time computation device computes an arrival time by accounting for a scheduled departure time and scheduled periods of stopping at en route points. Thus, even when the user loads or unloads freight into and from the vehicle at each of en route points, an accurate arrival time is computed.
Preferably, the route setting operation enables preservation of locations which have been entered in the past as a location history, and also enables selection of a starting location, a destination and an en route point from the location history list, to thereby allow easy selection of the starting location, the destination and the en route point.
According to the present invention, because locations which have been entered in the past are preserved in the history list, a location which is less frequently used can be selected from the history list without having to register the location in the registration list. A location thusly can be entered quickly without performing a burdensome retrieval operation, such as a map retrieval operation or a name retrieval operation.
Preferably, when selecting a route, the route setting operation accounts for assignment of an arbitrary weight to each of straight-ahead travel, a right turn, a left turn, and a U-turn.
According to the present invention, a weight to be assigned to each of straight-ahead travel, a right turn, a left turn, and a U-turn can be arbitrarily entered by the user in accordance with the user""s desire.
Preferably, the route retrieval operation enables preservation of at least one route previously utilized by the user as a route history list and retrieves a route by prioritizing the at least one route preserved in the route history list. That is, the route used most frequently is given the highest priority, the route used secondmost frequently is given second-highest priority, and so on for all the routes in the history list.
According to the present invention, since a route with the highest priorityxe2x80x94among those including the entered en route and/or destination pointsxe2x80x94is retrieved, a route satisfying the user""s desire is retrieved. The user is thus guided to drive a vehicle along the road which the user uses everyday, thereby enabling the user to drive safely.
The present invention also provides a recording medium having recorded thereon a processing program for use with a vehicle-mounted navigation system, which system detects a current position of a vehicle and retrieves a route to a set destination, thereby guiding the vehicle along the route, the program including:
a route setting operation for entering route setting information desired by a user, said route setting information including a starting location, a destination, an en route point, and at least one of a direction in which the vehicle is to approach the destination and a direction in which the vehicle is to approach the en route point; and
a route retrieval operation for retrieving a route to the destination on the basis of the route setting information entered in the route setting operation such that the direction in which the vehicle is to approach at least one of the destination and the en route point matches an approach direction set by the user.
Accordingly, the present invention avoids a case wherein a median strip may hinder the vehicle""s approach to a destination, or avoids a case wherein a commercial vehicle may not be able to load or unload freight. Therefore, a commercial vehicle can arrive quickly at a destination by way of a number of en route points.
Preferably, in the case of left-side driving, the route retrieval operation enables retrieval of a route such that at least one of the destination and the en route point is situated on the left side of the vehicle when the vehicle approaches the destination or the en route point. Similarly, in the case of right-side driving, the route retrieval operation enables retrieval of a route such that at least one of the destination and the en route point is situated on the right side of the vehicle when the vehicle approaches the destination or the en route point.
Accordingly, the present invention avoids a case where, in the case of left-side driving, a commercial vehicle approaches a destination from a direction in which the destination is situated on the right side of the vehicle so as to prevent the loading or unloading of freight despite a necessity to do so. Alternatively, the present invention avoids a case where, in the case of right-side driving, a commercial vehicle approaches a destination from a direction in which the destination is situated on the left side of the vehicle so as to prevent the loading or unloading of freight despite a necessity to do so.